Commercial kitchen exhaust removal systems are employed as a primary method of ventilating the workspace for chefs, foodservice personnel, and the patrons of foodservice establishments. As the grease-laden vapor is emitted from the cooking appliance line, the plume generated by the heating of the cooking rises into the kitchen exhaust system along with grease vapor, combustion by-products, and airborne contaminants.
As a fire prevention measure intended to reduce the quantity of cooking grease into the kitchen exhaust removal system, filtering of the kitchen exhaust is provided at the source of the exhaust hood, prior to the exhaust duct itself. However, traditional means of filtering the exhaust only trap a small percentage of grease and associated contaminants within the exhaust air stream. Consequently, grease-laden vapor is pulled through the primary grease removal device, and deposited on the components of the kitchen exhaust removal system including the exhaust filters, hood plenum, exhaust ductwork, and the exhaust blower.
Deposited grease within the exhaust filters, hood plenum, exhaust ductwork, and the exhaust blower must be regularly removed by a professional cleaning contractor in order to prevent fires within the kitchen exhaust removal system. Cleaning of the kitchen exhaust system normally involves cleaning of the exhaust blower, interior of the vertical and horizontal exhaust ductwork, the exhaust hood filters, plenum areas, and the exhaust hood interior itself. Such professional cleaning usually involves processes such as steam cleaning and/or pressure washing.
As cooking appliances are used on a daily basis, deposition of grease occurs greatest nearest the source of the cooking appliances, and daily reheating of the appliances will tend to re-liquefy grease residue deposited within the exhaust filter, plenum areas, and the exhaust ductwork. Natural migration of this deposited by-product induced by the exhaust blower leaves a continuous stream of grease, beginning at the grease removal device, through the interior of the exhaust ductwork, and into the exhaust blower. The interior of the exhaust blower typically experiences rapid grease soiling due to (i) fluid flow of the grease-containing air stream through the exhaust blower, (ii) paddling of the grease-containing air stream by exhaust blower blades, and (iii) the change in direction of the grease-containing air stream via the exhaust blower cowl or blower scroll housing (depending upon design), and discharge if applicable.
Between professional exhaust cleaning operations, significant volumes of grease can accumulate within the exhaust blower itself and within the exhaust ductwork. Leakage of grease from the exhaust blower housing onto the roof surface remains an ongoing challenge for many foodservice establishments. Cooking by-products damage almost all commercial roofing materials available today, and impact of the destruction of commercial roofing at foodservice establishments due to grease potentially interrupts bonds or warranties offered by the roofing installer, the contractor, and/or the construction company.
Although attempts have been made to address the problem of grease accumulation on rooftops of buildings, further efforts are needed. There exists a need in the art of effective methods and products for addressing the problem of accumulation of grease within a kitchen exhaust removal system, as well as on a building rooftop.